Under pressure to resign, the chancellor of the University of California, Davis, on Saturday called police use of pepper spray on seated Occupy protesters "chilling" and established a task force to look into the incident.

A campus police officer, in a sweeping motion, sprayed protesters point blank on Friday before other officers moved in. Eleven people were treated on site for effects of the yellow spray. Two of them were sent to the hospital, university officials said.

"Yesterday was not a day that would make anyone on our campus proud; indeed the events of the day need to guide us forward as we try to make our campus a better place of inquiry, debate, and even dissent," Chancellor Linda P.B. Katehi said in a statement.

The incident set off a flood of comments on the school's Facebook page, most of them critical of police and the administration.

Protesters rallied again Saturday evening, chanting "resignation" and "we are peaceful, you are not."

In a news conference, Katehi refused calls from faculty members and others for her to step down, saying she did not violate campus policies and that she has worked to make UC Davis a safe campus.

"Very unexpected, sad and very inappropriate at least on the face of it," she said of the incident, adding she wants the task force to look at how students can safely express their opinions. Officers sent in to remove tents had been encircled by protesters, creating a safety issue, police said.

Katehi later told CNN's Don Lemon that she considered the police actions "unacceptable," but stressed she has no plans to step down.

"We really want to look into this very carefully and take action ... make sure that it will never happen again on our campus," she said.

The Davis Faculty Association, citing incidents at other campuses, demanded "that the chancellors of the University of California cease using police violence to repress nonviolent political protests." It called for greater attention to cuts in state funding to education and rising tuition. Its board demanded Katehi resign, saying she exhibited "gross failure of leadership."

"Student debt has reached unprecedented levels as bank profits swell," the group said on its website.

After written and verbal warnings, officers reminded the protesters they would be subject to arrest if they did not move their tents from the quad, Morain said. Many protesters did decide to remove their tents and equipment, officials said.

A group of about a dozen protesters sat on a path with their arms interlocked as police moved in to remove additional tents. Most of the protesters had their heads down.

At one point, protesters encircled the officers and blocked them from leaving, Morain said. Cut off from backup, the officers determined the situation was not safe and asked people several times to make room, Morain said. One officer used pepper spray when a couple of protesters and some of the 200 bystanders moved in, she added.

One of the protesters hit by the spray told CNN's Lemon that she was still feeling some after-effects Saturday evening.

"I was shocked," said Sophia Kamran. "When students are sitting on the ground and no way of moving to be violent, being totally peaceful, I don't understand the use of pepper spray against them."

Kamran said she and others had sat down in "solidarity" of five others she said were arbitrarily arrested by officers.

Annette Spicuzza, chief of campus police, said officers in riot gear were unable to get out after they were encircled.

A use of force review will "determine whether we made all the right decisions and handled it the way we should have handled it," Spicuzza told reporters.

Ten people were arrested during the face-off, Morain said late Friday. Tentative citations were failure to disperse and lodging without permission.

Morain said the pepper spray was used in lieu of batons. "Obviously, they use this only as a last resort," she said of the officers.

Katehi said the incident followed weeklong peaceful demonstrations on the campus over the cost of higher education and other issues.

"During the early afternoon hours and because of the request to take down the tents, many students decided to dismantle their tents, a decision for which we are very thankful," she wrote. "However, a group of students and non-campus affiliates decided to stay. The university police then came to dismantle the encampment. ... As indicated in various videos, the police used pepper spray against the students who were blocking the way. The use of pepper spray as shown on the video is chilling to us all and raises many questions about how best to handle situations like this."

Katehi said the task force made of faculty, students and staff will review the events and provide a report within 90 days.

"This report will help inform our policies and processes within the university administration and the Police Department to help us avoid similar outcomes in the future," she said.